Concave pushbutton



FIG. 1 is a front perspective view of the concave pushbutton;

FIG. 2 is a back perspective view of the concave pushbutton;

FIG. 3 is a front view of the concave pushbutton;

FIG. 4 is a back view of the concave pushbutton; and,

FIG. 5 is a left side view of the concave pushbutton. The right sideview, top and side view and bottom side view are identical to the leftside view.

The ornamental design for a concave pushbutton, as shown and described.